High-speed precision data camera



June 22, 1965 w c 3,191,183

HIGH-SPEED PRECISION DATA CAMERA Filed May 18, 1959 3 Sheets-Sheet 1FIG. I

m; RUIIIIIHIH IIHHIH] F, 2 INVENTOR.

F'Rsosmcz P WARRICK BY h; M

ATTORNE Y5 June 22, 1965 WARREQZK 3,191,183

HIGH-SPEED PRECISION DATA CAMERA Filed May 18, 1959 3 Sheets-Sheet 2 INVEN TOR. Fnsasmcz R Wmzmcx AT TORNE Y5 June 22, 1965 F. P. WARRICK3,191,133

HIGH-*SPEED PRECISION DATA CAMERA Filed May 18, 1959 3 Sheets-Sheet 5 IFIG. 5

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a ARMATURE O J f IO IO INVENTOR. 5 Panama R WARRKK ATTORNEYS UnitedStates Patent 3,191,183 HIGH-SPEED PRECISION DATA CAMERA Frederick P.Warrick, Clarkston, Mich, assignor to McDonnell Aircraft Corporation,St. Louis, Mo., a corporation of Maryland Filed May 18, 1959, Ser. No.813,731 1% Claims. (Cl. 352-419} This invention relates to high-speedcameras and particularly to cameras which are adapted to record themovement of a rapidly moving object.

In designing rapidly moving objects such as aircraft and missiles, it iscustomary to study the performance of such objects or components thereofby mounting them on a sled which guides their movement in apredetermined path along a track and observing their operation duringthis movement. In order to record such high speed performance, it hasbeen customary to locate cameras at predetermined intervals along thetrack which are adapted to record and make a moving picture of theaction of the objects. Since the objects are moving at very high speeds,as for example from 200 to 3500 feet per second, the length of time thatan object will be in the field of any particular camera is quite limitedand the length of film exposed in any particular camera is short.However, since the entire time consumed in traveling along the track isshort, it has been considered necessary to start the cameras at thebeginning of the test and permit them to run continuously in order toinsure that each camera will record the movement of the object past thecamera. it can be appreciated that it may thus become necessary to use asubstantial quantity of film in each camera. Only a very small portionthereof will contain any images of the moving object. In addition to theobvious waste of film, which in the case of color film results insubstantial cost, the valuable time of experienced personnel is used inediting the film in order to obtain the usable portion thereof.

It is therefore an object of this invention to provide a high-speedprecision data camera which utilizes a very short length of film butwill definitely insure recording of the movement of the object beingtested.

It is a further object of the invention to provide such a camera havinga 35 millimeter or larger frame size.

In accordance with the invention, a plurality of cameras of particulardesign are located at spaced intervals along a track and the cameras areelectrically connected so that as the sled bearing the object beingtested moves along the track it triggers each camera in the successionat the proper instant to thereby insure that the camera will record themovement of the object past its aperture.

In the accompanying drawings:

FIG. 1 is a perspective view of a camera embodying the invention.

FIG. 2 is a longitudinal vertical sectional view along the axis of thelens.

FIG. 3 is a fragmentary sectional view taken along the line 33 in FIG.2.

FIG. 4 is a fragmentary sectional view taken along the line 44 in FIG.3.

FIG. 5 is a fragmentary sectional view taken along the line 5-5 in FIG.2.

FlG. 6 is a fragmentary sectional view taken along the line 66 in FIG.2.

FIG. 7 is a wiring diagram of the camera embodying the invention.

FIG. 8 is a diagram of the camera apparatus for recording the movementof an object.

Referring to the accompanying drawings, camera 10 comprises a housing 11on which a magazine 12 is removably mounted. As shown in FIG. 2,magazine 12 incamera aperture 22.

eludes an intermediate wall 13 which divides the magazine into a supplycompartment 14 and a take-up compartment 15 having openings 16, 17,respectively, communicating with the interior of the camera housing.Film housing 12 is light tight and is mounted on the camera in alight-tight relationship thereto.

A. strip of film F in random looped relationship in the supplycompartment 14 is passed over an idler roll 18 in the compartmentthrough opening 16 into the camera housing. The film is then threadedbetween an idler roll 19 and a sprocket 2%) having teeth Zta thereon forengaging the perforations of the film strip. The sprocket 20 is drivenas presently described to feed the film downwardly through a verticallyslitted block 21 having an aperture 22 therein.

The film then forms a loop below the aperture block 22 and is threadedbetween an idier roll 24 and another pcripheral portion of sprocket 2%and passes upwardly through a slit 25 in a guide block 26, throughopening 17 and then into the take-up compartment 15 of the film magazine12. Block 2; is provided with curved grooves 27 which provide aclearance for the teeth 21 on the sprocket Zti. idler roll 24 isrotatably mounted on a lever 28 which is pivoted on intermediate andlongitudinal wall 29 of the camera housing as at 3 3. Lever 28 is lockedin position holding idler roll 24 adjacent the periphery of sprocket 269by a pin 31 which engages an opening 32 in intermediate wall 29 (PEG.6). When the pin 31 is retracted from opening 32, it permits the lever28 to be pivoted away from the sprocket 2.0 and thereby facilitates thethreading of the film upwardly through slit 25.

Referring to FIG. 3, sprocket 2% is keyed to a shaft 32 which isrotatably mounted in intermediate Wall 29 by spaced ball bearings 33,34.

As shown in FIGS. 2 and 3, a polygonal prism 35 is mounted in a cage 36for rotation about an axis transverse to the axis of aperture 22. Cage36 is rotatably mounted within a housing 37 mounted in intermediate wall29. Aligned stub shafts 3%, 39 on the cage 36 are journalled on oppositeend portions of housing 37 by ball bearings 42, 43 and 41.,respectively.

Cage 36 is generally cylindrical and is provided with a plurality ofrectangular openings 44 in the cylindrical wall thereof. The axes ofopenings 44 are perpendicular to the faces 45 of prism 35. As the cage36 and prism 35 are rotated clockwise as viewed in FIG. 2, the prismcauses successive images to be directed from the camera lens to theexposure area or aperture 22 and travel in the direction of movement ofthe film.

Cage 36 and prism 35 are rotated as a unit by a shaft 46 through bevelgears 4'7, 48 keyed to shafts 38, 46 respectively. Shaft 46 isjournalled in the camera housing with its axis parallel to and spacedfrom the axis of the A shutter 49 in the form of a disc is fixed onshaft 46 and is provided with a plurality of regularly spaced openings5% which are adapted to be successively brought into registry with theaperture of the motor shaft 52 is coupled to a stub shaft 53 journalledin a transverse wall 54 of the camera housing by ball bearing 55 (FIG.3). A gear 56 keyed to the shaft 53 meshes with a smaller gear 57 keyedto shaft 46. When the motor 51 is energized, the shaft 46 iscontinuously rotated thereby continuously rotating the shutter 49 andthe prism 35. The shutter and prism are thus operating to directsuccessive images toward the exposure area as more fully described in mycopending application entitled High Speed Camera, Serial No. 627,012,filed December 7, 1956, now Patent No. 2,952,183.

In accordance with the invention, provision is made for rotating thesprocket only during a predetermined interval of time while motor 51 isrunning. In this way film is fed past the camera aperture only duringthe short period of time when the object to be photographed is travelingpast the camera. The means for rotating sprocket 20 includes a shortshaft 58 journalled by ball bearings 59 in the camera housing. Shaft 58extends longitudinally of the camera and is parallel to shaft 46. A

driving connection is formed between the shafts 32, 58 by bevel gear 60on shaft 32 which meshes with bevel gear 61 on the adjacent end of shaft58.

A clutch 62 adjacent the other end of shaft 58 provides a drivingconnection between shafts 53 and 58 when energized. Clutch 62 is of theelectromagnetic type and includes a housing 63 mounted on the camerabody. A coil 64 is mounted in housing 63 and surrounds a core 64a fixedto the shaft 53. An armature plate 65 is mounted for axial movement on amember 66 fastened to the shaft 58. The armature plate 65 is yieldinglyurged axially out of engagement with core 64a by a leaf spring 67. Whenthe coil 64 is energized, the armature 65 is drawn axially of the shaft58 into magnetic locking engagement with core 64a to form a drivingconnection between shaft 53 and shaft 58. Core 64a includes a ring 64bof friction material adjacent armature 65. Core 64a comprises an innerring mounted on the shaft 53 and an outer ring 64d separated from theinner ring by the friction material 6412 and plastic Me. In this manner,the outer ring 64d is electrically insulated from the inner ring toinsure the flow of flux between the armature 65 and the housing 63 whenthe coil 64 is energized.

In order to insure that the sprocket 29 will maintain the desired speed,a fly wheel member 67 of substantial mass is mounted on the shutter 49.Thus when motor 51 is rotating shutter 49, and the driving connection tothe sprocket 20 is made by energizing clutch 62, the large inertia offly wheel 67 prevents any substantial lowering of the speed of rotationof the motor.

The wiring diagram for each camera is shown in FIG. 7 and includes asource of alternating current applied to lines L L Capacitor 75 is inseries with a half wave rectifier 76 and a limiting resistor 77. Whenthe switch 78 is closed, current is supplied to the field winding 70 andarmature 71 of the motor of the camera. In addition, a capacitor ischarged to a direct current voltage. A switch 74 is actuated by movementof the object along the track, thereby connecting the capacitor 75across the coil 64 of the clutch and providing a rapid current build upin the clutch coil 64. This current decays rapidly, but i is ofsufficient duration to insure that the film has been driven through thecamera. The coil 64 then comes deenergized.

Referring to FIG. 8 which is a diagram of the camera apparatus, in use,a plurality of cameras 10 embodying the invention are located at spacedpoints along the track T which defines the path of travel of the object0 being tested. The switches 74 which control the clutches of therespective cameras are located at spaced points along the track inadvance of the respective cameras.

At the beginning of the run, current is supplied to the motor 51 of eachcamera so that the motor rotates continuously thereby continuouslyrotating the prism 35 and shutter 49 of each camera.

As the test begins and the object moves along the track on the testsled, the sled successively closes switches 74. As each switch 74 isclosed, it causes the clutch 62 of its respective camera to be energizedthereby driving the sprocket 20 and feeding a relatively short length offilm through the camera. Since the action of each camera is controlledby movement of the sled, it is assured that the camera will record thepassage of the object.

the first few frames of the length of film are almost full size. As aresult, because of the high speed at which the object being photographedis moving past the camera, only a relatively short length of film isneeded to record the movement of the object. In most instances, a lengthof 10 feet is more than adequate where the film speed ranges from aboutten to seventy feet per second, or about 300 to 1200 35 mm. frames persecond. It is thus necessary to only use a few feet of film for eachcamera as contrasted to a full reel of film. This not only results in asubstantial saving in the cost of the fihn but in addition, considerabletime is saved in processing and editing.

I claim:

1. In a camera for photographing the movement of an object moving past apredetermined point at a high speed, the combination comprising meansforming an aperture which defines an exposure area, means for feeding astrip of film past said aperture, lens means for forming an image,'meansfor directing successive images toward said exposure area and movingsaid images in the direction of movement of said film across saidexposure area, drive means for continuously operating said latter meansat a substantially constant speed, clutch means operable to establish adriving connection between said drive means and said strip feeding meansat a time when said drive means and said image directing and movingmeans are operating and said strip feeding means is at rest, the inertiaof said drive means and said image directing and moving means beingsubstantially greater than the inertia of said strip feeding means sothat the speed of operation of said drive means and said image directingand moving means is substantially unaffected when said drivingconnection is established.

2, The combination set forth in claim 1 wherein said image directing andmoving means comprise a polygonal prism having spaced parallel surfacesmounted adjacent said exposure area against which said lens meansdirects an image, and a cage supporting said prism for rotation aboutits axis.

3. The combination set forth in claim 1 wherein said strip rfeedingmeans comprises a sprocket positioned in advance of said exposure areaand having teeth thereon for engaging the perforations of a strip offilm past the exposure area.

4. In a camera for photographing the movement of an object moving past apredetermined point at a high speed, the combination comprising ahousing having an aperture which defines an exposure area, a sprocketmounted for rotation in said housing in advance of said aperture aboutan axis generally parallel to the plane of said aperture and havingteeth thereon adapted to engage the perforations of a strip of film andthereby move the film past said aperture when rotated, a polygonal prismhaving spaced parallel surfaces mounted adjacent said aperture with itsaxis parallel to the plane of said aperture and perpendicular to thedirection of movement of the film past said exposure area, a cagesupporting said prism for rotation about its axis, means for directingan image onto said polygonal prism whereby when the prism is rotatedsuccessive images are directed to the exposure area and moved in thedirection of movement of said film across said aperture, a substantiallyconstant speed motor mounted on said housing, a disc type shuttermounted adjacent said exposure area for rotation about an axis generallyperpendicular to the plane of said exposure .area and adapted to moveacross said exposure area,

means forming a driving connection between said motor, said shutter andsaid cage, and clutch means for establishing a driving connectionbetween said sprocket and said motor when said sprocket is at rest andsaid motor is operating for driving said sprocket in synchronism withsaid cage and shutter, the inertia of said motor, shutter, cage andprism being substantially greater than the inertia of said clutch andsprocket so that the speed of rotation of the motor is substantiallyunaffected when said driving connection is established.

5. The combination set forth in claim 4 wherein said means forming adriving connection between said motor, said shutter and said cagecomprises a first shaft mounted for rotation in said housing, said motorhaving a drive shaft extending at a generally right angle to the axis ofrotation of said sprocket and said cage and parallel to the axis of saidfirst shaft, means forming a driving connection between said drive shaftand said first shaft.

6. The combination set forth in claim 5 wherein said means forming adriving connection between said drive shaft and said sprocket comprisesa second shaft axially aligned with said drive shaft, a clutch betweensaid drive shaft and said second shaft, a third shaft on which saidsprocket is fixed, and means forming a driving connection between saidsecond shaft and said third shaft.

7. In a camera for photographing the movement of an object moving past apredetermined point at a high speed, the combination comprising ahousing having an aperture which defines a substantially flat exposurearea, a sprocket mounted for rotation in said housing in advance of saidaperture about an axis generally parallel to the plane of said aperture,said sprocket having teeth thereon adapted to engage the perforations ofa strip of film and thereby move the film past said aperture whenrotated, first guide means associated with said sprocket for maintaininga portion of said film in contact with said sprocket in advance of theaperture and second guide means associated with said sprocket formaintaining another portion of said film in contact with said sprocketbeyond said aperture, a polygonal prism having spaced parallel surfacesmounted adjacent said aperture with its axis parallel to the plane ofsaid aperture and perpendicular to the direction of movement of the filmpast said exposure area, means for supporting said prism for rotationabout its axis, lens means for directing an image onto said polygonalprism whereby when the prism is rotated successive images are directedto the exposure area and are moved in the direction of movement of thefilm across said exposure area, a disc type shutter mounted adjacentsaid exposure area for rotation about an axis perpendicular to the planeof said exposure area and adapted to move across said exposure area, asubstantially constant speed motor mounted on said housing, meansforming a driving connection between said motor, said shutter, and saidpolygonal prism, and magnetic clutch means forming a driving connectionbetween said sprocket and said motor when said sprocket is at rest andsaid motor is operating for driving said sprocket in synchronism withsaid prism and said shutter, the inertia of said first-mentioned drivingconnection and said motor, prism and shutter being substantially greaterthan the inertia of said clutch and said sprocket, so that the speed ofrotation of said motor, prism and shutter is substantially unaffectedwhen said driving connection is established.

8. The combination set forth in claim 7 including means associated withsaid housing providing a supply compartment for a randomly looped stripof film adjacent said first guide means, and means associated with saidhousing adjacent said second guide means providing a take-up compartmentfor randomly receiving said strip of film.

9. The combination set forth in claim 7 wherein said shutter supports aflywheel fixed thereto to increase the inertia thereof.

10. in a camera apparatus for photographing the movement of an object,the combination comprising a plurality of cameras, each said cameracomprising a housing having an aperature which defines an exposure area,a sprocket mounted for rotation in said housing in advance of saidaperture about an axis generally parallel to the plane of said apertureand having teeth thereon adapted to engage the perforations of a stripof film and thereby move the film past said aperture when rotated, apolygonal prism having spaced parallel surfaces mounted adjacent saidaperture with its axis parallel to the plane of said aperture andperpendicular to the direction of movement of the film past saidexposure area, a cage supporting said prism for rotation about its axis,means for directing an image onto said polygonal prism whereby when theprism is rotated successive images are directed to the exposure area andmoved in the direction of movement of said film across said aperture, asubstantially constant speed motor mounted on said housing, a disc typeshutter mount ed adjacent said exposure area for rotation about an axisgenerally perpendicular to the plane of said exposure area and adaptedto move across said exposure area, means forming a driving connectionbetween said motor, said shutter and said cage, and clutch means forestablishing a driving connection between said sprocket and said motorwhen said sprocket is at rest and said motor is operating for drivingsaid sprocket in synchronism with said cage and shutter, the inertia ofsaid motor, shutter, cage and prism being substantially greater than theinertia of said clutch and sprocket so that the speed of rotation of themotor is substantially unaffected when said driving connection isestablished, and means individual to each said camera and responsive tothe movement of an object toward said camera for actuating the clutchfor its respective camera so that the strip feeding means of saidcameras are operating successively.

References Cited by the Examiner UNITED STATES PATENTS Re. 9,960 1 2/ 81Muybridge -1 995,061 6/ 11 Duhem 352- 1,978,500 10/34 Meyer 95l1.52,091,357 8/37 Goldsmith 346141 2,194,808 3/40 Pooley 8824 2,269,8621/42 Rose 1786 2,417,076 3/47 Hickman 352-116 2,906,162 9/59 Taylor 95112,952,183 9/60 Warrick 352-119 2,967,211 1/ 61 Blackstone et ,al 88-1JULIA E. COINER, Primary Examiner.

EMIL G. ANDERSON, Examiner.

1. IN A CAMERA FOR PHOTOGRAPHING THE MOVEMENT OF AN OBJECT MOVING PAST APREDETERMINED POINT AT A HIGH SPEED, THE COMBINATION COMPRISING MEANSFORMING AN APERTURE WHICH DEFINES AN EXPOSURE AREA, MEANS FOR FEEDING ASTRIP OF FILM PAST SAID APERTURE, LENS MEANS FOR FORMING AN IMAGE, MEANSFOR DIRECTING SUCCESSIVE IMAGES TOWARD SAID EXPOSURE AREA AND MOVINGSAID IMAGES IN THE DIRECTION OF MOVEMENT OF SAID FILM ACROSS SAIDEXPOSURE AREA, DRIVE MEANS FOR CONTINUOUSLY OPERATING SAID LATTER MEANSAT A SUBSTANTIALLY CONSTANT SPEED, CLUTCH MEANS OPERABLE TO ESTABLISH ADRIVING CONNECTION BETWEEN SAID DRIVE MEANS AND SAID STRIP FEEDING MEANSAT A TIME WHEN SAID DRIVE MEANS AND SAID IMAGE DIRECTING AND MOVINGMEANS ARE OPERATING AND SAID STRIP FEEDING MEANS IS AT REST, THE INERTIAOF SAID DRIVE MEANS AND SAID IMAGE DIRECTING AND MOVING MEANS BEINGSUBSTANTIALLY GREATER THAN THE INERTIA OF SAID STRIP FEEDING MEANS SOTHAT THE SPEED OF OPERATION OF SAID DRIVE MEANS AND SAID IMAGE DIRECTINGAND MOVING MEANS IS SUBSTANTIALLY UNAFFECTED WHEN SAID DRIVINGCONNECTION IS ESTABLISHED.